Furnace dust trap



April 26, 1949. s, D. RICH 2,468,108

FURNACE DUST TRAP Filed Aug. 10, 1944 IN VEN TOR. Sam 0. Rick Patented Apr. 26, 1949 UNITED STATES PATENT OFFICE 3 Claims. 1

The present invention relates to furnaces, particularly of the household type, and has for an object the provision of a simple and inexpensive dust trap whereby the escape of dust and smoke into the furnace room is eliminated during the operations of tending the furnace and removing the ashes.

Another object of the invention is to provide a device of this kind which controls furnace room air currents in the vicinity of the firing front of the furnace and which assists in preventing back drafts in the fiue from releasing smoke through the fire door openings into the free atmosphere of the furnace room.

Still another object of the invention is to provide a light-weight device of this kind which can be folded into a thin flat parcel that is inexpensively packed for individual shipment through the mails and otherwise and which may be packed and stored in quantity in a minimum of space.

A further object of the invention is to provide a device of this kind which is readily applied to and removed from operative relation with a furnace. r

These and other important objects are attained by the means described herein and exemplified in the accompanying drawings in which:

Fig. 1 is a fragmental front elevational view of a household furnace having a device of the invention operatively associated therewith.

Fig. 2 is a view taken on line 22 of Fig. 1.

Fig. 3 is a perspective view showing a device of the invention in folded and collapsed condition.

Fig. 4 is a fragmental side elevational view of a household furnace with a device of the invention permanently secured thereto and disposed in an inoperative position.

Heretofore the operation of household solid fuel burning furnaces has been universally attended by the escape of ash dust into the furnace room in varying degrees during the operation of shaking the furnace grates and during the removal of the ashes from the ash pit. The heavier portions of the escaping ash may settle throughout the furnace room, while the lighter particles are air borne from time to time to various parts of the household and they constitute not only a source of so-called household dirt and damage to house furnishings but in addition to this they are more recently recognized as inimical to the health of occupants.

Insofar as is known, the previous attempts to combat these evils have resulted in relatively complicated and expensive devices, many of which were not entirely satisfactory for various reasons.

By the present invention there is provided a very simple and easily accommodated structure which sets up a beneficial control of the furnace room air currents in the immediate vicinity of the firing front thereof so that when the fire door and, or, ash pit door, as well as the control louvers or draft openings of either, are open these furnace room air currents are constrained to follow a general course into the furnace itself and to carry with them floating dust particles, traces of smoke and fumes, due to the back drafts in the furnace, which would otherwise eventually travel about in the free atmosphere in the room. By this same means that portion of extraneous household dust which may come into the effective area controlled by the device is likewise trapped and removed.

In its preferred form the device of the invention is arranged and constructed so that it is of practically universal application to the wide variety of household solid fuel burning furnaces that are now in use. In this form also the device is very light in weight and is arranged to be collapsed or knocked down into a. thin fiat form as shown in Fig. 3.

In the preferred construction the dust trap indicated generally at H! comprises a top wall member ll of fiat light gage metal having a length somewhat in excess of the width of a furnace ash pit door, while the width of said top wall is desirably greater than the width of the firing door so that the top wall will project somewhat beyond the edge of the firing door when the latter is open at approximately right angles to the front of the furnace. Movably or removably connected, for example by an integral hinge portion I2, is a side wall member l3 which may be somewhat narrower than the top wall but which has the rear edge l4 normally disposed in a common plane with the corresponding rear edge l5 of the top wall II. The side wall I3 is intended to provide an imperforate bafile from the fioor to the elevation of the top of the firing opening l5ll of a furnace. In order to accommodate the side wall to varying heights of furnace firing doors, an extension or slide i6 is applied for longitudinal adjustment over the bottom of wall l3. This may be provided in any suitable fashion, for example, by providing opposed edge channels IT on the longitudinal edges of the extension I 6 so that the side wall l3 may be slidably adjusted therein. A slot I! in extension It has a bolt and nut structure, indicated at l8, inserted therein and through a perforation in the wall I3. I prefer to provide the under side of the projecting portion of the top wall II with a plurality of longitudinally disposed parallel creases l9 which are impressed very lightly into the sheet metal to facilitate the manipulation of the front edge of the top wall by hand to form a slightly down-turned front flange 20 when desired. The extreme forward edge 2| of the top Wall may be finished smooth by forming a bead thereon.

It should be noted that in its preferred form the rear edges l 5 and Id of the top and side walls respectively are left with raw edges so that should the contour of the front casting of the furnace require it, the edges of said members may be notched to accommodate projections on the furnace. Due to the thickness of the metal such notchings may be effected by means of an ordinary scissors or a tin snips.

It will be understood that the structure of the hinge i2 may be of any convenient form, such as by integral tubular complementary hinge portions arranged in staggered relation on the respective members and connected by means of a pintle 22 formed of a suitable length of ordinary stiff wire.

Applying the dust catcher I to 'a'household furnace such as 23, the extensible slide wall i3i6 is positioned at approximately 90to' the top wall it and the said top wall is positioned immediately above the top of the fire door opening I53. The slide or extensible member I is then adjusted relative to the side wall It so as to span the distance from the top wall to the floor 24 of the furnace room and, upon tightening the nut and bolt structure it or a comparable securing means, the side wall serves as a'vertical leg to support the top wall at its one end. In those furnaces on which there may be found a horizontal rib or flange closely above the top of the fire door opening I59, the device, when extended to an inverted L-shape, may be disposed against the furnace with a rear edge of the top Wall resting on sucha rib ledge. With the raw rear edges of the top wall and side wall in substantial abut-- ment against the furnace front, the dust trap of the invention is thus fully supported for use without any further fastening means. Should the furnace to which the device is to be applied, 'be Without a suitable horizontal front ledge above the fire door opening I58, as is commonly found and as illustrated in the accompanying Figs. 1 and 2, the top wall I i is placed upon the top edge of the fire door 25 when the latter is open and at approximate right angles to the front of the furnace and this is the operative position in which the fire door should remain when the furnace grates are shaken and when ashes are being removed through the ash pit door opening 26.

The furnace illustrated in Figs. 1 and '2 has the commonly found arrangement wherein the firing door opening I50 is located immediately. above'the ash .pit door opening 26, and the respective doors 25 and 27, which control said openings, have their respective latches 250 and 210 on a common vertical side of said doors. The latch keepers 25l and 211 are accordingly located on the furnace front adjacent the so-called latch side of the respective door openings.

In operation, with the firing door .25 and ash pit door 27 in open position as shown, .and the device sup-pcrted in operative position with side wall i3l$ extending adjacent the latch side of the door openings 26l 50 (see Fig. 1), the smoke pipe 28 would have the fiue damper 29 in open position in .the'manner well known to most persons as proper whenever the fire door is open for any reason whatsoever. At that time the optimum draft is established through the fire door opening, the smoke pipe and the stack or chimney. The effective zone of suction or air intake through the fire opening is extended forwardly of the furnace by the positioning of the dust trap of the invention as illustrated. Air currents in the furnace room at this time are constrained to pass between the side wall l3--|6 and the open firing door and ash pit door 25 and 21. The draft or suction into the firing door I50 is thus increased so that in this zone it is possible to freely shovel ashes from the ash pit 26 and deposit them in a bucket or other receptacle seated on the floor within said zone without the usual pufling and scattering of ash dust into the free atmosphere of the furnace room. Instead the liberated fly ash and dust is entrained in the air currents flowing from various directions to the front of the resulting trap or draft structure and from the lateral space between the bottom of firing-door 25 and ash pit door 21. Floating dust particles of extraneous origin likewise becomeentrained under the altered condition of air currents in the furnace room and their movementinto the fire door opening I50 can be readily observed with the aid of concentrated beams of light operating in a condition of subdued generallighting or of substantial' darkness.

It will be understood that whereas the readily removable 'du'st trap thereinbefore' described is of the preferred form' for .the purpose of independent merchandising, a substantially similar structure may be permanently appended to a furnace in any'suita'ble mannerby hin-ging the rear edge I5 of the topwall l I to the front of the furnace casting-above the fire door so that the device may be foldedicompactly against the furnaceby first folding the side wall aboutits hinged connection to lie on top of the top wall and then tilting the top wall upwardly about its rear hinged mountinggasshown in Fig. 4.-' In .Fig. 4 the side wall I30 is shown disposed between the furnace and the upturned top wall i I l, the top wall being hinged as at 30- on a horizontal'rib or bracket 3| suitably aflixed to. the frontof the furnace 23. When it is desired to utilize the dust trap and the back draft bailling. effects of the device it will be unfolded to assume a position as shown in Figs. 1 and 2.

Under conditions of low barometer and wind, it will be-found desirable to leave the device of the invention operatively associated with the front of the. furnace so that when momentary back drafts in the chimney cause slight puffs of smoke to escape from: the fire door draft control 32 (see Fig. 2) the resumption of .normal draft will again'draw the escaped smoke and fumes back into the furnace through the opening from whence they originally escaped, due to the .control zone which isqset upr-between the top wall member and the adjoining side wall-member.

What is claimed is:-

1. The combination with a household furnace havinga door controlled firing opening and an ash pit opening, of a dust trap device comprising a topwallmemberadapted for edgewise abutment horizontally' cn the front of the furnace above the. fire door opening, and a sidewall member extending downwardly from-one end of said top wall to the floor and serving as a supportinr said. end, the other endof said top wallbeing adaptedto be supported bythe fire door in its open position.

2. A dust trap forming device for a household furnace consisting of a top wall and a side wall extending downwardly from one end of said top wall, said walls adapted for edgewise abutment with the front of a furnace having an ash pit door and a firing door with their latches on a common side for partially enclosing the door area in front of the furnace and bounding said area continuously along the latch side of the ash pit and firing door openings of the furnace and along the top edge of the firing door opening, the free end of the top wall adapted to rest on the top of the fire door of the furnace in its open position.

3. A furnace dust trap forming device comprising a top wall and a side wall member hingedly connected to form an inverted L-shaped housing for deposition against the front of a flunace which has a fire door controlling a firing opening therein and an ash pit door controlling an ash pit opening therein, said top wall adapted for support at its free end by said fire door in its open position, said side wall member adapted to rest endwise on the floor and to extend upwardly alongside said openings in the furnace,

SAM D. RICH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 536,097 Reading Mar. 19, 1895 836,745 Ferren Nov. 27, 1906 962,152 Kline June 21, 1910 1,106,101 Knapp Aug. 4, 1911 1,166,506 Widdrington Jan. 4, 1916 1,321,027 Gerlach Nov. 4, 1919 1,438,719 Peffer Dec. 12, 1922 1,500,955 Matz July 8, 1924 1,567,927 Ebert Dec, 29, 1925 1,630,927 Ebert May 31, 1927 1,767,312 Russell June 24, 1930 2,078,959 McDonnell May 4, 1937 2,151,486 Ramel et a1 Mar. 21, 1939 FOREIGN PATENTS Number Country Date 157,012 Germany Dec. 10, 1904 

